mtd: nand: Get rid of needless 'goto'

Using "goto" and "switch" statement only makes it harder to follow
control flow and doesn't bring any advantages. Rewrite the code to avoid
using "goto".
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/nand_base.c

@@ -2162,7 +2162,7 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
 static int nand_read_oob(struct mtd_info *mtd, loff_t from,
 			 struct mtd_oob_ops *ops)
 {
-	int ret = -ENOTSUPP;
+	int ret;
 
 	ops->retlen = 0;
 
@@ -2173,24 +2173,18 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from,
 		return -EINVAL;
 	}
 
-	nand_get_device(mtd, FL_READING);
-
-	switch (ops->mode) {
-	case MTD_OPS_PLACE_OOB:
-	case MTD_OPS_AUTO_OOB:
-	case MTD_OPS_RAW:
-		break;
+	if (ops->mode != MTD_OPS_PLACE_OOB &&
+	    ops->mode != MTD_OPS_AUTO_OOB &&
+	    ops->mode != MTD_OPS_RAW)
+		return -ENOTSUPP;
 
-	default:
-		goto out;
-	}
+	nand_get_device(mtd, FL_READING);
 
 	if (!ops->datbuf)
 		ret = nand_do_read_oob(mtd, from, ops);
 	else
 		ret = nand_do_read_ops(mtd, from, ops);
 
-out:
 	nand_release_device(mtd);
 	return ret;
 }